If the wavelength of an electromagnetic wave is too long or too short,
a. it cannot be seen
b. it is no longer a wave
c. it is no longer an electromagnetic wave
d. it becomes a sound wave

The focal length of a relaxed human eye is approximately 1.7 cm. when we focus our eyes on a close up object, we can change the refractive power of the eye by about 16 diopters. (a) does the refractive power of our eyes increase or decrease by 16 diopters when we focus closely? explain. (b) calculate the focal length of the eye when we focus closely.

Work out sian speed for the first 30 minutes of her journey. give your answer in km/h.

What is the energy of a photon of ultraviolet radiation with a frequency of 4.4 × 1015 hz? planck’s constant is 6.63 × 10–34